Managing OmniSwitch 6855 Series Stacks
Reloading Switches
OmniSwitch 6855 Series Hardware Users Guide
September 2011
page 7-33
No Switches In the Stack Have Saved Slot Information
If a full reload is issued and no switches in the stack have unique slot numbers, slot numbers will be
assigned beginning with the switch with the lowest MAC address. (This can occur if the
boot.slot.cfg
file
has been deleted from each switch’s /flash directory—e.g., by issuing the
stack clear slot
command for all
modules in the stack.)
The switch with the lowest MAC address is assigned slot number 1 and given the primary management
role. The switch connected to stacking port A of the primary switch is automatically assigned slot
number 2 and given the secondary management role. Stack cabling is then used to determine the dynamic
slot numbering of the remaining modules in the stack. The switch immediately adjacent to slot 2 is
assigned slot number 3 and given an idle role, etc.
An illustrated example of this method for assigning slot numbers and management roles is provided on
pages
7-21
and
7-22
.
Some Switches Have Saved Slot Information, Others Do Not
If only
some
switches in the stack have
boot.slot.cfg
files in their /flash directories, the system software
will first read the contents of these files and then dynamically assigns unique slot numbers to any switches
that do not have saved slot information. The primary management role will be given to the switch with the
lowest
saved slot number. The secondary management role will be given to the switch with the
second-
lowest
saved slot number. All other switches will be assigned to idle roles.
When unique slot numbers are dynamically assigned by the system software, a
boot.slot.cfg
file is auto-
matically generated with the new slot information. Because all switches now have unique saved slot infor-
mation, any subsequent
reload all
commands issued will cause the stack to come up as described in the
section,
“All Switches Have Unique Saved Slot Information” on page 7-32
.
Two or More Switches Have Duplicate Slot Information
If a full stack reboot is issued and the same slot number is found in the
boot.slot.cfg
file of two or more
switches, the switch with the lowest MAC address is allowed to come up and operate normally. Mean-
while, any other switches with the duplicate slot number come up in
pass-through mode
.
The pass-through mode is essentially an error state in which a switch has been denied primary, secondary,
and idle roles within the stack. When a switch is in pass-through mode, its Ethernet are brought down and
cannot pass traffic. It is for this reason that users should always check the current saved slot number for
each switch before issuing the
reload all
command. To check the current saved slot information across the
stack, use the
show stack topology
command. For detailed information on pass-through mode, refer to
“Pass-Through Mode” on page 7-13
.
